X-ray technology has existed for more than 100 years, but in spite of repeated efforts no one has found a way of solving the problems involved in making X-ray machines portable. Now, thanks to an innovative European Union (EU) funded multinational research project, that breakthrough has at last been achieved.

The new device opens up the possibility that X-rays can be used in ambulances and other 'in-the-field' medical situations, making it possible to bring much faster medical diagnosis and treatment to patients than ever before. This would be of particular importance in remote locations, when transporting the patient to the nearest conventional X-ray machine might result in long delays in treatment. The portable device is also expected to enable easier, more reliable and lower cost use in a range of commercial applications such as security screening or product quality inspections.

The secret of the new, hand-held X-ray machine, known as NANORAY, lies in replacing the heated filament of existing devices with a 'cold' system which does not require heating.

Because this 'cold' system is able to emit electrons at room temperature, the NANORAY prototype eliminates the need for the power and heat management systems that are required to heat the filament to the necessary 2000°C in current devices. Together with the fact that its use of nanotechnology enables it to reduce the size of the source tube, the overall effect is to reduce the weight of the device by a remarkable 75% compared to non-portable devices - to a mere 5Kg.

As well as allowing size and weight reduction, the 'cold' NANORAY machine brings another instant advantage. As we all know from domestic lightbulbs, heated filaments burn out on a regular basis. The average lifespan of an X-ray tube in a traditional machine is less than one year, with most failures caused by the filament  a costly problem that is eliminated at a stroke by the new 'cold' system, which the NANORAY consortium confidently expects will provide a lifespan up to 10 times longer than the heated filament.

It all sounds simple; however the reality of developing the NANORAY technology was anything but. The 10-member consortium, funded under the EU's 7th Research Framework Programme (FP7) and comprising research organisations and specialist SMEs from around Europe, had to overcome a number of technical challenges.

The system the consortium developed is based on an arrangement of microscopic, cylindrically-shaped carbon molecules known as 'carbon nanotubes', a thousand times thinner than a human hair. Carbon nanotubes have unique physical properties  mechanical, electronic, thermal and optical  which make them ideal for purposes such as the NANORAY project. But they are hard to handle, and their behaviour is still not fully understood.

The consortium is currently in the process of evaluating a number of private investors who are willing to invest in the further development of the NANORAY technology. If the technology can be fully perfected, the benefits will not stop with the reduction in size and weight, the significant reduction in maintenance costs, and the improved reliability, impressive though all these are. The NANORAY device is also able to generate X-ray images of a far higher resolution and clarity than previously possible. Moreover, the faster response time of the NANORAY machine, due to the fact that the cold cathodes can work immediately, without the need for a 'warm-up' period, compared with the traditional X-ray device, means that in medical settings patients need to be exposed to the X-rays for a shorter period.

Still at the prototype stage, the NANORAY system is, as yet, not licensed for use outside the laboratory. But tests are continuing and the NANORAY consortium's ongoing contacts with a number of international companies and research centres keen to develop the technology further will play the crucial role in determining the future possibilities for the device. With its potential applicability in a range of fields outside the medical sphere, such as quality inspection, further development will depend on the investor that NANORAY decides to partner with and which application that investor chooses to focus on.

Whatever market application that turns out to be, it is clear that the NANORAY consortium has taken a major step towards a new, portable, cost effective and better quality X-ray device for potential use in a wide range of situations, whether medical, industrial, or both.